SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7377472c4be6dbb7330e67dc3466dc4fdb0e862338408de864e1362018782fe3' 
  AND token = 'FphzI0hGROGkuNX4eKTuR6KYwMDmaYswpQXdET2ZWUk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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