SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53154194a5e516329f18a5c6fcd43afbd7333a3dcb885e41077a4a4e663249e7' 
  AND token = 'LsvwUySxKXfJWhS0P4TGOmtGzEZfLOA3SJOpQ2VEI3g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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