SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfb93d3821722d2229112a5bd90f232c170162708b1139c58c6b763d294d578c' 
  AND token = 'eXsJCTn7laW+2T4MBFVkf4YnuDmz2NqwoZulF/wKkXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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