SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f8b71fa0ba69ca886aa45643b6ce37e388320cb74670371b5590165c3f6a175' 
  AND token = 'GG9ErRoVohjfGFoxrA8p8VLRUMMibMNZnSCKQBD8+8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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