SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05a154293abd8778be41ed27a88ebda106240baf28b4ccdb67d1b3df7b58fcbd' 
  AND token = 'fBz9tXzPR41fC7RoFDHjy9PI5wsyjCEDo0aeIAyb31Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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