SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd37175d1b0f08d23b87742fcab179043835bd8484a0dbadb114ffd41ea554b2' 
  AND token = 'kzlJvks8IWj2JV0djA9Na/PLveQVxjvz36qkE8RKeyE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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