SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c969bfd9f886edb557e4141fa4d234db2499d580fa48254d3e6063a716504c96' 
  AND token = 'usYq4dDjF9TL3xnPbwen+FVFEzPXcITXHfEPoN26uwI=' 
  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"
    }
  }
}