SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2701eafc020e4de94d732bf78958be92469b8e2745325ae69c35adba4168513e' 
  AND token = '3vDIMjHjZGmieGGXxiduP/jMZ0eerdZ4nqUWhYyZtmI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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