SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5e7793007f03f05ec781897a5758f4a92fc44ee5e9cc394efb45c61c3419429' 
  AND token = 'VI0qIUA2zuMjbTkPKBf04T5QfWbuNtl2kMfkbDNYFwc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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