SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '767698320483b6ea55878829d7fedbf8fe28590a2de774c2eb496c040f4cfdb8' 
  AND token = 'ZnajiIXFGQw+5Ihd5cUN6P107yYUv+SQhyLKxzyzVek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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