SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '40fc21f8600861aca21dbaaf27326effbc848adca44035f5db5d936511552c61' 
  AND token = 'VAGpOA+6Db087KlYSa3umZ5+1Cl7kbaVEvwA9tOlFR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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