SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ceafa20a61998a27fa839c7d7d08dbd9658e251af604c21f50651ba3c45899b7' 
  AND token = 'XgEJnxsyz2Izw8jQJrRQ82L85rtn3HfIxF28zHMiynQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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