SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62cb0d582f6d3f3dda28b7282d417b1af7cd8b78ea052c3e80cfa323b7e96889' 
  AND token = 'u+awCFYHqM6J/PxFt9YfsHKG0fiNN0J6OQvUKkSS/B4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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