SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62fd67022dce340d62caeafb968555f90c2909eaecfd2b84d5a1307458f36e94' 
  AND token = 'oQWwUpxi+Ve4wzIvTJh7VxGQLW5EGY1Ehs/We3VFFbU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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