SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed73d0478c898857b093b20c868e7def3e9d3129252a4aebaff259b277decaac' 
  AND token = 'EXQUT+pWzmY+d+/jiUxPHxe1aEQCDONQlzR06Mm5374=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}