SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '604bb9b44073090756c935c785e9afaa7a4c41aa97e1c1919ab455745c75e941' 
  AND token = 'XCGuqVG93LXvNMFT0xytZQAeyfQk8PTkUI+wZnKNe08=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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