SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5a3eee5098ca35c8373c45477db040e8e85998fa0d762af88e7856ecaa8253de' 
  AND token = 'o/nUTt1+xuahvX0Kf64g120puk16sbF4ovhyhlVmLXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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