SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd7270f7fd32dc842129e8396c8206dd2d86446a8513256792580343e023fb8e7' 
  AND token = '4SlpotV0ryMnM16UCNVwbuDPbVQmDgQQjUVK+0MCPqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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