SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7be454d64c765833b235e07a863e5254417976e38db15d76f87617ee4ac8c568' 
  AND token = 'HOxVFilNPwLC2o07eKAd1lIUxzIY5pQ/C1ZcHyowpcg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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