SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9de805125220b124314bcd45625d8d72731ee706ccb381a2a3b8e9cc07b43da' 
  AND token = 'o0OJ2ouin4hS5qhDDh8uZSggVWHiq/JHCfXpGwfKWeg=' 
  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"
    }
  }
}