SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62a8a344b0bcdd6282b8e69b11682d87ebc564577b2ccf1b54a53f33cdcf5a19' 
  AND token = 'MPPX0qbJMJmONX5c24jKyt9owTnZNDHYDnKcUDMiac0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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