SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bb623ca32d690563fa2d08537292d928a0902f05f1ea68650f3c565125321bbf' 
  AND token = 'E3eD5c0ELQUjHCtoihK9pM+IZXLtyw1noQDgZ6KB5Bk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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