SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88ec62594364575a25de56f807a5297cd690b42ef8a37c630e90825df9aeb3bb' 
  AND token = 'EQg6XaiYz/8NnAvaBXjhjvi4zwvrnWbdBoXmd+pBqa8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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