SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e23d4054e530f20d8c050cbcf2d0ac18e3e3d378d8784dfca1350dd9275f4945' 
  AND token = '5cBXBxin/wnTwZNZJnRtfdCugbiRTor1RU8fRuQdLDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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