Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd2f6252e4d80a33a384bcbfaa35bc35ff2e815592276f9a8a61a208b93e9346' 
  AND token = 'yUl6VOqwqcmQ6P6o+hMco87AadkosTLYb3Saec3dQck=' 
  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"
    }
  }
}