SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d6ffb04316db78aebc37bda66d6d261d010535fe7778d688ed4333d49af7fab' 
  AND token = 'KRFAB1laG7bexjAwu7VRfCBa9usH7nJmaSMDqPZN46I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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