SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9418742ef822593c73661857ec02a8278f70a2a57caa9d5ab3fec190ed436ff' 
  AND token = 'FVJNWeU7xhBUFEYdtrKkAafHpF4hCgiN7gFdPKyA4pM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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