SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5a302f8af6ddc9a9075cdffd5f8511626f758c36db2beec45f47e493403cf55' 
  AND token = 'Za9nqLIkqmtbqshL2wFZUBjFIMs5UPq4IMsPpKpvR5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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