SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5894fa4e8a138f47a14c4b9e828fdf24bf42f6363ababe398a1086c933fa7d74' 
  AND token = 'KVgMgL9LrrdIg8YACHMP0WiBE/RDaWJq2TNkV732xwE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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