SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48c99fa892e69af5ea1850c163e3bafd8955b3082a35af765bd4f8545ab7e94a' 
  AND token = '7eLFpY6+IVujd1ypb4XPNUZdUVBRJvNoIhwAkkFiZkE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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