SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1da1a5d211cbdae6ff66610a13bb7f2bfec3b430d1c530de1a39bd0162af218' 
  AND token = '2rrlf397fJZZoO3MEHQjGW2bnvdEtnpx4mUAmvIVqYc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}