SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa47c5ac62cc14c8ca7fb7d34c760628386f3fcae5591bf84dda6a016dbea4cc' 
  AND token = 'VQWqcr4HVhvarBawYJxGNRHtgTL6fS1ppD0QvePDcxo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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