SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cce0ec0d30450e6a67afb4b37199781be77c096268c3689a47975a1d11f10733' 
  AND token = 't74vFXm9/T1rug9Nv4WrLPkhNBMyEVjRphI0bFQMYOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}