SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc5d8112df1773d58f48d56b344baed4723a5ed5bba23e01afe658c02607b72b' 
  AND token = '6cI/GDM/LPkgXkg+JozgVW4QB4/DsNJr+Nyht1w/vvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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