SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2353426ded2b9fcd7f41d54fa4b6825fb2c48f07447439226484f01709dde814' 
  AND token = 'gxB4M5aQG579DrjhR73lz0INESK/hzn1mRiWAi+KZGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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