SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6ddd522661a692caa4885783dee60550736aac86232c228cfce869bc076dd66' 
  AND token = 'Z7uekZlaK+3xkQ1lvfTp+l1ZpAsTBi2qtdVYYGq6kl0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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