SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb3c9f2d0d2eba5dbd3ab1bd5100b38dccefdd15dc1d5b9cac9f0742ce35376b' 
  AND token = 'Pu1Bm9jNqxkSXeO8BOIWMilwdlvvhlwkVwO7q2sGPok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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