SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '40e2bbf603d089abdf47d7f01e11b8889bd8d382fc40b67b2e76170773c854e4' 
  AND token = 'N1yj6w9h/tzHAXiu5CSh0na2r6OJaCYcFpKMS0Jq+Bw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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