SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '4c176ecaf9469bf5d9ed4d6872b872fd1f0b7f09f06b7357488c367e2047cb84' 
  AND token = 'uHWCq1quGY6gnzhwOc4Qa4RMtq+G9N1M8OgzNstwR+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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