SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16996d7c3442fe45a83f918aec36372984f7e1cf878de726cb2c15e8cddf8865' 
  AND token = 'dDrAvGEcgrp77VxYFUQ3cGx+C9uWj8TiogujX3GoUcc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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