SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c00e02c8b168b88bb44218ecbe3439f5cf7d74be33891b7ed729ecece79421c5' 
  AND token = 'XlhG5EjK8sbqgha7tsHkSLt4paMvBkfzxTf/C+EyIZo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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