SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1bf2262a61c5f87e53651a8a8fb970328a95c019d5d6da040b8327f5688dcbd' 
  AND token = 'YQXbnZSF2/OS9gNB3HeWdjyLee/cfAGFuwRjlPURBjM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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