SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fce8f87c5498ac08d0a127e556c3eb247e0873f69a7dbbe2fa81bf90845d572d' 
  AND token = 'ZVpq3LgrfKX9CxDjBPFqE8G8UY/VQ6uyi5hjtHDaL3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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