SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3527abd1fea5c5ff1db7b2339ba572ca227c36428194d32eeb2863c532e5dbe0' 
  AND token = 'mVKt+wHJhFyLK1N7/5uT8+1Pp1oS4j2Zs/QqQDWsfGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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