SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '435b2298bad52c30020690d4fc59baa3e911d16e05800c94a71a6e3f65103548' 
  AND token = 'VomKV+CYkmDPxqK0BhrSXYpDoutMQTe92ES2Df+xKkg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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