SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7c737b0a144b2ac8653ceef091cfee32c54281f7e5a8a69c963b7a64711afc28' 
  AND token = 'sb5TpNXpYW0KDk6JmvkBWoF3ismsXQkPDTcbpTHOv7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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