SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f27c63271bb8395ea30183ff822d5651556154df18d56247a2b7a04eb61c56c7' 
  AND token = 'eN4gkJ3JgxI4c2XMEVnQx5+ZX2jwlGAz/Zb7DwHrSF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}