SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65034b65861754d43ffd4a6f36cdd03de52b0600d090a0e34bb90eca321b13eb' 
  AND token = '6cI6EaLsAcexmGZsvahmyZMOVF/t3X+NyUdFue9pSvM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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