SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '85fa68b75eba0228b9471bb95e0d3afbfa58c06eeed1dce754ebb03fc60fded8' 
  AND token = 'z3lLQ2Bwq4xHc2ne/gR4NgPMq1pEM4w4IOS+qpkXEW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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