SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '885bd4b1f6924e0d41e68861a38e877e9682339cdef011751104179b3b109d7b' 
  AND token = 'UKKEZm4zN5uQa1uMkQFS6HcZpQE6J79sBSV07DXdYgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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