SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '914eea97fa77bb558a21d9be73cc570131741fd417cecbddfeeb2c0b23a7c773' 
  AND token = 'JRPfeSQlz2eD/juTTqPO/KY6NmLZvYO+EUOl+huWnu0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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