SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5369b365ba57b233da1064c337415bd7b638f2e2d78d6e1ff4a151fc20a8250c' 
  AND token = 'hLvlbzBrpHTL5gr2jTxdOCI1/EzXGuId6dIi/qrOoOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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