SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3029d64d4e64d8a82a29decfbd7afd3fe95b1f7fd235a3c5cf6e6cf524fc0ce4' 
  AND token = 'gXjfYE+1P4gCGtAVBMqeA+ah+m8ppSsU8+4UPzYv3vY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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