SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c386294ed200b0e63f9783565cb76591d94cb5c79082651c9d08dd1ddf02b14' 
  AND token = 'FwgN+51hX1lEwtzpK+SqmkhSG/s+ufv8ycEsH5Ijsd8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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