SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '717daa33da9bbe0b6be0e278b7ebf930d5928a0ee1617e8f4232f90481a90b51' 
  AND token = 'g0y0YJUr9NK0/x9YfGMonvXFlPallBGBU9Zq9WMrkXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}