SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd12c3f6d689f462cd9528796ba693b1fb7931919ff9994402ec9a9beb062292f' 
  AND token = 'FWyQk4OJREsFnad0+1V01v+Xps/yK+eGHXL+GYZfFB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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