SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37e306ee9d69d7d6345f2e79277332054ec2d41498cb14bd16c2f99d39a4aed8' 
  AND token = 'PcfeLbT7w+7QNFh7IL6IWxZ7Lei6hrZqHN/7r3CiYfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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