SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4ef3ad8115acc5ac8941dbe3200114df91387f9a769db51de5799b88744d259d' 
  AND token = 'e3jHF8/yHLOi4bWt2/a2dVB8fW4BeLlOvuMXhxrht9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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