SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a7308e2cecce0843044e1b115f967bf789031b9c1b22c8bc2ad962b739f43cd9' 
  AND token = 'FKO65WDmWBK25D79k3CCiEgruShZFeQ9XL3kQC2qNJs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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