SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b754e34e891ea65ed225c83e49fd991a4075def7ba32fd2293e5459bf3346c8' 
  AND token = 'RhJNgQewQ8zOmCJbW7mIuP1Aup4Gk84rUW+isoioUCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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