SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd367186a8beb86593a236e1ab0731500aaa51920ba97e77ad88c301174940679' 
  AND token = 'nNs0DZvefVRvWOkJFDE0JTHclNuu4LtuWbWkhoUfRKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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