SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27ea18ad8b6669d98fa4bbda21e3d9069bd8f8b8bf1410c95745c537aea080e7' 
  AND token = 'syaqa5J25LbMnFT/7YxnOnJsnLCZalZgfv43VskR0wQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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