SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23d302cbd6acac98175add2edeb1ff1f5207f0838354433935ae602207dcb44b' 
  AND token = 'slhwRW+JGRB5ZJ5Oh7PKWPhq1b/s8w6dvGx6FVHcDU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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