SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecebc570f585b9d7916036bc07e24de3c4929e8f0c02e3990b040866feea4cc0' 
  AND token = 'XbKVMZnvYn5rhCi4918ZiRko18JycwjjABTJWvu3OwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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