SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e99c74525d31bd365da397d4a62424fdf9559770be25bbb807e43cbe2db7b188' 
  AND token = 'biLWRgd+HRQ1LjnVw0i8q4FVlwnAXI3+bSPdhLwkjLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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