SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5c5c30c033de569f2613483b43fddd0269b8d00d7e59842e62561982ad1ff7a' 
  AND token = '0ZdwW2oRAnvpXwxNVwcyxPjOEpO8DIb6F9PXYTEGdRA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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